Monolithic optoelectronic chips are known on which a plurality of laser diodes that can be driven independently of one another are realized. From the plurality of laser diodes, at a point in time under consideration, one of the laser diodes serves for data communication, while the others are kept as redundant laser diodes for the case where the laser diode currently being used fails or falls below prescribed quality criteria in particular with regard to the light power. Thus, the failure rate of laser diodes is 50 to 200 ppm, depending on the operating temperature. By using redundant transmitting sources, it is possible to reduce the failure rate of a transmitting device to less than 10 ppm.
If the laser diode currently being used fails or falls below prescribed quality criteria, a change is made to a different one of the laser diodes and this laser diode is used for data communication. The sequence of the laser diodes used is fixedly prescribed in this case. In this case, there is the risk of the replacement laser diode likewise falling below prescribed quality criteria.
It is furthermore known to use all the laser diodes of a chip having a plurality of laser diodes simultaneously for data communication, the same signal being emitted by the laser diodes. In the event of a failure of one of the laser diodes, the further data communication is effected using the remaining laser diodes. However, this solution has the disadvantage that the laser operation is effected with a high current consumption and a high temperature.